Gain and Bandwidth Enhancement of X-band Compact Dielectric Resonator Antenna with Defected Ground Structure

This article presents an effective technique of gain and bandwidth enhancement for the dielectric resonator antennas (DRAs). The technique incorporates defected ground structures (DGSs) in the DRAs. Two DGS-based rectangular DRAs (DGS-RDRAs) with compact dimensions (39.6 mm x 29.2 mm) are proposed for the RADAR, satellite downlink, and other X-band communications. The DGS-RDRAs are designed by engraving circular and rectangular slots in their ground planes. Two prototypes of the proposed DGS-RDRAs are fabricated and measured so as to validate them. The measured results illustrate that the DGS-RDRA with a circular slot provides an impedance bandwidth (IBW) of 51.8% (8.413-14.29 GHz). The IBW for the rectangular-slotted DGS-RDRA is 18.69% (8-9.65 GHz). The antenna gains of 4.13 and 4.05 dBi are achieved by the circular-slotted and rectangular-slotted DGS-RDRAs, respectively. Other antenna parameters such as reflection coefficient and impedance of the antenna are also analysed. The resultant parameters obtained by the proposed DGS-RDRAs are compared with the similar type of existing DRAs in the literature. The comparisons further validate the proposed DGS-RDRAs as the best suitable candidate for the X-band applications.